Liquid level gauge



Oct. 19, 1948. H. L. wooD LIQUI'DvLENvEL GAUGE Filed Dem.` '7, 194eINVENTOR. Howard L, Wood Patented Oct. 19, 1948 UNITED `STATES PATENTyOFFICEv n LIQUID LEVEL GAUGE Y HowardL. Wood, Oskaloosa, IowaApplication December 7, 1946, Serial No. 714,790

. l This invention relates generally to Aliquid level gauges and inparticular to a gauge for indicating the level of oil in the crankcaseof an automobile engine. iA

Most oil gauges now commonly used with automobile engines consistmerely' in a metal rod, insertible within a crankcase opening, andhaving low and "fu1l graduations marked on its lower end. In determiningthe oil level in the crankcase the rod is rst removed and wiped cleanand then reinserted Vwithin the crankcase and removed'a second time toobserve theextent to which the oil has adhered to the rod relative tothe graduations.

This method is generally unsatisfactory due to the fact that when theYoil is clean and/or of a lightweight, it is not readily visible on theoil rod. Also, unless the rod after being wiped clean is insertible asfar as possible into the -crankcase the oil level reading is erroneous.Further, on inserting the rod for reading purposes, care must beexercised to keep the lower end of the rod from rubbing against anyoil-covered surface on the side wall of the crankcase opening.

It is an object of this invention, therefore, to provide an improvedliquid level gauge.

A further object of this invention is to provide an oil level gaugewhich is eicient in operation to positively indicate the oil level inthe crankcase of an automobile engine. Y

Another object of this invention is to provide an oil level gauge whichclearly indicates visually the level of oil in an engine crankcaseregardless of the weight'or cleanliness of the oil.

Still another object of this invention is to provide a gauge forvisually indicating the level of oil in the crankcase of an automobileengine, which is of a compa-ct and simple construction, operable to anindicating position concurrently with its initial removal from the-crankcasa and readily adapted for application to a wide variety ofautomobile models. y f

A feature of this invention is found in the provision of a gauge forindicating the level of fluid in a container, in which an inner tube isin telescoping relation within an outer tu-be of a shorter length thanthe inner tube.V The lower end of the outer tube is closed and formedwith a longitudinally extended slot which is closed to Ytrap liquid inthe inner tube, onV movement of the inner tube to a telescoped position,andjopened to permit the ow 'of liquid intoV theinner tube, on movementof the inner'tube to an extended position. A yieldable means on 'theopen end of the outer tube is adapted to .move and'hold the 3 Claims.(Cl. i3-425.4) Y

' 1 innerV tube in itsextended position. The inner Y the accompanyingdrawings, in which:

Fig. 1 is a perspective View of the liquid level gauge of thisinvention;

Fig. 2 is a perspective view of the front portion of an automobile, withparts Ibroken away, illustrating the application ofthe gauge of thisinvention to an automobile engine;

Fig. 3 is a longitudinal sectional view 'of the gauge; and

Fig. 4 is illustrated similarly to Fig. 3 with parts being shown inchanged positions.

With reference to the drawings, the oil level gauge of this invention isillustrated in Figs. 1, 3 and 4 as including an'outer large tube I0, ofva metal material, closed at one end I4, which for convenience shall behereinafter referred.` to as its lower end. Spaced from such lowerend'ld is a pair of oppositely arranged longitudinally extended slots I6which constitutefluid openings.

A body member II (Figs. 3 and 4) of a cylindrical shape, and mounted onthe top end I8 of the large tube I0, is formed with a central borehaving an internally threaded reduced section I9 and an enlarged section2|. vThe top'end I8 of the tubeIll is threadable within the reducedsection I9, with the junction of the bore sections I9 and 2l being denedby an annular shoulder 22.

Slidably supported in a telescoping relation within the large tube I0 isa small inner tube or valve member 23 composed of a transparent plasticmaterial and of a length longer than the large tube I B. When the smallturbe is in its fully contra-ated position within the large tube, asillustrated in Fig. 3, its' outer endY 24 projects from the top endy I8of the large tubeand outwardly from the body member Il through theenlarged bore section 2 I.

Mounted in a concentrically spa-ced relation about the outer end 24of'the'small tube 23` is a hollow cylindrical cap member" 26 integrallyformed at its inner end with an annular projection or stop `member 2'I`of a size and shape providing forV its slidable movement within theenlarged bore section '2L A ring-shaped nut 28 mounted about the 4capmember`26 and thread-A able on Ythe outer end 2 9 -of Ythe body memberI'I isl engagable with the' projection 21 to, limit the movement of thesmall tube 23 outwardly from the large tube I0. The movement inwardly ofthe small tube 23 relative to the large tube Il] is defined by theengagement of the stop member 21 with the annular shoulder 22.

The small tube 23 is moved and held in its outermost position (Fig. 4),defined by the engagement of the projection 21 with the nut 28, by theprovision of a coil spring 3i mounted about the outer end 24 of thesmall tube and arranged in compressionbetween the top end I8 of thelarge tube I and the closed end 32 of the small tube 23.

When the small tube 23 is in its outermost position, the inner end 33thereof is Within the longitudinal confines of the slots I6, whereby theslots are open to the space inside of the small tube. On movement of thesmall tube 23 toits contracted position within the large tube (Fig. 3)the inner end 33 thereof is below the lower edges or sides 34 of theslots I6 whereby the slots are closed relative to the space within thesmall tube 23'.

In the operation of the. oil gauge of this invention assume that it isto be used in indicating the oil level in the, crankcase 35 of anautomobile engine 31 (Fig. 2). Thegauge, with its parts arranged asillustrated in Fig. 4, is inserted within a usual oil gauge or crankcaseopening, indicated at 38, to a position at which the inner end 39 issupported on the peripheral sidewall of the gauge opening 38.

A felt gasket 4| may be mounted on the large tube l0 at a position,against the inner endV 3.9 of the body member Il to prevent dust, gritand the like from entering the crankcase about the gauge during a normaloperation of the. automobile. With the gauge thus, inserted in the crankcase, oil in the crankcase ows through the slots I6 and into the spaceWithin the small tube 23 to a height corresponding to the level of theoil in the crankoase.

Tovisually observe the level of the oil in the crankcase a4 laterallyextended fingerV grip 42 integrally formed on the body member IT ishooked with one finger of the hand, and the closed end of the cap member26 is pressed by the thumb of the same hand to move the inner tube 23against the action. oi the, spring 3| to its contracted positionillustrated in Fig. 3, at which the projection 2T is against the annularshoulder 22. By virtue of this inward movement of the inner tube 23 itslower end 33 is moved below the bottom edges 34 of the slots I6 wherebyto trap the oil within the inner tube 23.

With the small tube 23 maintained at its inward or contracted position,the gauge is removed from the crankcase opening 33 and the level of theoil in the transparent tube 23 is visually observed through the slots I6which constitute observation windows in the large tube I3. Suitablegraduations, such as indicated at 43 and 44, may be marked on the largetube Ill to indicate low and "full oil readings, respectively;

To assure the free entrance of the oil from the crankcase into the innertube 23, vent openings 46 and 41 are formed in the outer end 24 of thetube 23 and in the cap member 26, respectively, which openings arecontinuously open to the atmosphere.

On completion of an oil-level reading, the gauge is reinserted withinthe crankcase 38 and the cap member 26 released. 'I'heA oil in thecrankcase is thus again permitted, to enter the space within the innertube 23 whereby to provide for a later oil reading in the same manner asdescribed above.

From a consideration of the above description, it is seen that theinvention provides an oil level gauge which is of a simple and compactconstruction, and positive in operation to accurately indicate the oillevel in an engine crankcase.

The inner end 33 of the small tube 23 functions as a valve relative tothe slots i6 to control the flow of oil into and out of the space'withinthe small tube, which is acted upon by the spring 3l so as to always bein a slot-opening position, except when the cap member 26 is manuallydepressed. As a result an oil level reading can be taken on an initialremoval of the gauge from the crankcase.

l Although the invention has been described with respect to a preferredembodiment thereof, it is to be understood that it is not to be solimited since changes and modifications can be made therein which are'Within the full intended scope of this invention as deiined by theappended claims.

I claim:

l. A gauge for indicating the level of liquid in a container .betweenpredetermined high and low liquid levels comprising, a large tube.member closed at its bottom end and having a slot spaced from suchbottom end, a small tube member slidable within said large tube having atransparent portion movable across said slot and an outer portionprojected from the top end of said large tube, a body member mounted onthe top end of Said large tube having a bore therethrough, with theouter portion of Vsaid small tube being extended through the bore insaid body member, stop means for limiting the slidable movement of saidsmall tube member relative to said large tube memben, means carried onsaid body member for yieldably moving and holding saidsmall tube at aposition extended outwardly from said large tube, with said small tubebeing lmovable within said large tube, against. the action of saidyieldable means, to close said slot, and means for supporting the gaugewithin said container such that saidv slot extends between saidpredetermined high and low liquid levels. l

2. A gauge for indicating the level 0f liquid in a container betweenpredetermined high and low liquid levels including a pair of teleseopingtubes with the larger one of said tubes being closed at its lower endand the smaller tube being extended from the top end of said larger tubewhen in a telescoped position, said larger tube having a longitudinallyextended slot spaced from the closed end thereof, and the inner portionof said smaller tube being formed of a transparent material, a bodymember mounted on the top end of said larger tube having an openingtherethrough to receive said smaller tube, stop means for limiting thetelescoping movement of said smaller tube relative to said larger tube,yieldable means on said body memberadapted to move and hold said smallertube in an extended position outwardly from said larger tube such thatthe inner end of said smaller tube is above the lower side of said slot,with said inner end, on movement oi said smaller tube. to its contractedposition, being movable, to a position below said lower side of theslot, and means supporting the gauge within said container such that theextremities of said slot are substantially within said predeterminedthigh and low liquid levels.V

3V. A gauge for indicating the level of Va liquid in a container betweenpredetermined high and low liquid levels comprising, a tube memberclosed at its bottom end, and having a longitudinal slot spaced fromsaid bottom end, a tubular valve member slidably movable within saidtube member to a first position at which the inner end thereof is belowsaid slot to close the same, and to a second position at which said slotis open to provide for a ow of liquid within said valve member, stopmeans for limiting the movement of said valve member between said twopositions therefor, with the inner end portion of said valve memberhaving a transparent section therein opposite said slot whereby thelevel of the liquid in said valve member is visually observed throughsaid slot, means for yieldably moving and holding 15 said valve memberin said second position, with said Valve member being movable againstthe action of said yieldable means to said rst position, and means forsupporting the gauge within said container such that said slot ispositioned between said predetermined high and low liquid levels.

HOWARD L. WOOD.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number

